Inflatable flood barrier

ABSTRACT

Disclosed is an inflatable flood defence or a water dam, the flood defence structure or water dam includes at least one inflatable chamber ( 12 ) having a front face ( 13 ), a rear face ( 15 ) and a multiplicity of interconnecting members ( 18 ) extending between the front and rear faces. This arrangement provides a rigid inflatable structure which is used as a flood defence and performs a reservoir for retaining water.

This invention relates to an inflatable flood defence, or a water dam.

Conventional flood defences are produced from rigid materials such as concrete or particulate materials such as soil, sand and stone. Such defences are permanent in nature and take up a large volume. They are also time consuming to build so they are either permanent structures erected on site, or, if prefabricated, cannot be deployed quickly in an emergency due to their size and weight. Also some structures are susceptible to erosion by flowing flood water.

Inflatable defences have been proposed by others to protect buildings from flooding, for example GB2411423A. However, these are not particularly strong and require unattractive permanent fixing around the perimeter of the building, ready to be inflated. These known inflatable defences are held to the ground or the base of the building because they would otherwise float away, and thus they require a high strength fixing at their base.

The inventor has realised that what is needed is a defence or water dam which is inflatable and needs no, or the minimum of site preparation. Such a defence can then be deployed quickly, where needed, and removed after use, so need not be permanently located.

According to one aspect the invention provides a flood defence structure or water dam including or comprising at least one inflatable chamber providing a front surface and a rear surface, the front and rear surfaces extending generally parallel and being interconnected by a multiplicity of interconnecting members extending across the chamber, and at least one of the surfaces providing a water barrier.

In this way an inflatable defence or water dam can be provided which is rigid when inflated by virtue of the interconnecting members. This rigidity means that the defence can, if necessary, be self-supporting and can be higher than other known inflatable structures. The structure is preferably water fillable without bulging because the interconnecting members hold the surfaces in place. This results in a heavy structure which will not lift in the flood water. As a result, it is not essential that the structure is fixed or sealed to the ground. Conveniently, the structure includes a skirt located at a lower region of the chamber, in use extending toward the flood water or impending flood water. The skirt may be arranged to lie on the ground adjacent the chamber. A substantially watertight seal between the chamber and the skirt may be provided.

In one embodiment one of the surfaces, or both surfaces are substantially impermeable to water.

Suitably the or each chamber is formed from so-called drop-stitch material. Said drop stitch material may have two polymer coated fabric sheets separated by a multiplicity of fibres or threads, each being attached to the inner sides of the sheets. The drop stitch material thus has a forest of fibres connecting the two sheets. When inflated with a fluid, the chamber formed from drop stitch material produces a rigid structure.

In one embodiment a chained series of chambers is employed having a sheet material join between adjacent chambers, acting as a hinge and/or a water seal between adjacent chambers.

Preferably the chambers may have spacer elements for spacing the chambers from an adjacent wall in use. Such spacers may be additional chambers of the type mentioned above.

In another embodiment a pair of chambers are arranged, spaced apart at their lower regions and coming together at their upper regions. The resultant pyramid shape improves the strength of the defence where the defence is free standing.

The series of the chained chambers mentioned above, or the pyramidal pairs of chambers mentioned above may be arranged in a polygonal manner when viewed in plan, for example a square or hexagon. The basin formed within the polygon may be filled with water and the floor of the basin may have a water impermeable layer sealed to the chambers of the polygon. Thus a water reservoir can be formed. Further, the polygonally arranged chambers may be connected together at their edges to form a continuous elongate watertight flood defence wall, or a series of reservoirs.

The invention extends to any novel feature described herein, or any novel combination of features described.

It will be understood that the invention can be put into effect in many ways and by way of illustration only, embodiments of the invention are described below, with reference to the drawings, wherein:

FIG. 1 a shows a sectional view from the side, of first embodiment of a flood defence, in operation;

FIG. 1 b shows an enlarged view of an element of the flood defence;

FIG. 2 a shows a plan view of a second embodiment of a flood defence, in operation;

FIG. 2 b shows a section along the line 2b-2 b in FIG. 2 a; and

FIG. 3 shows a third embodiment of the invention.

Referring to FIG. 1 a there is shown a conventional building structure 1 which has a concrete internal floor 3, and a cavity type 2 wall built on a foundation 4. The ground 5 outside the building 1 has a level 6 which in this case is flooded by flood water 8 to a level 7. To prevent the flood water 8 reaching the building 1 a flood defence system 10 is employed.

The flood defence 10 comprises an inflatable main chamber 12 providing a barrier to flood water 8. The main chamber 12 is backed by a supporting chamber 14, which in this instance is formed in the same manner as the main chamber 12. Water pushing toward the building will force the main chamber 12 toward the wall 2. The supporting chamber 14 will react against the wall 2 and hold the main chamber in place.

The main chamber has a skirt 16 which extends from the base of the chamber 12 toward and underneath the flood water 8.

Referring additionally to FIG. 1 b, this drawing is a more detailed view of the area ‘1 b’ shown in FIG. 1 a. Chamber 12 has a front woven fibre reinforced polymer sheet material 13 and a rear sheet 15 of the same material, which extend generally parallel. The front and back sheets are interconnected by a multiplicity of interconnecting polymer fibres or threads 18 extending across the chamber. The material described in this paragraph is known as drop-stitch material. The drop stitch material uses about 10 threads per square centimetre, which weave through the interior of the inner and outer sides 13 and 15, known as scrim, that forms the woven fibre. The outside of the chamber sides 13 and 15 are coated with pvc, in this instance, although other waterproof flexible coatings such as rubber or urethane can be used. The edges of the drop stitch material, for example edges 13 e and 15 e are glued and or heat sealed to provided a substantially airtight chamber.

The overall structure of the chamber 12 can be formed into a substantially air and/or watertight compartment, which when inflated provides a rigid structure with inherent mechanical strength to resist bending, tension, and compression. In particular, the structure can be water filled and yet still support itself .

In use the chamber 12 is deployed, for example just before a flood warning, and inflated initially with a gas, e.g air or CO2, to form its shape. The air will be released from a compressed gas tank stored inside the chamber 12, using a lever operable from outside the chamber. This action affords some protection from flooding, but the chamber 12 is not particularly heavy and so has a tendency to lift if not held down in flood water. Thus, although not essential, the chamber may then be partially or completely filled with water, particularly if it seems likely that flooding will take place following an initial warning. The water can suitably be added to the chamber from a hose pipe, while air is allowed to escape in a controlled manner from the top of the chamber 12 via an escape valve 17.

Alternatively, if no hosed water supply, or other water supply is.available, a one-way valve 18 can be employed at the base of the chamber 12 which allows flood water 8 to enter the chamber 12, but not escape. Since the pressure of the flood water 8 is likely to be no more than atmospheric, then compressed gas in the chamber can be allowed to escape to encourage the flow water to enter the chamber. If the gas is allowed to escape via the escape valve 17 at just above atmospheric pressure then, as the flood water rises, a higher level of flood water compared to the water in the chamber will cause the water to flow into the chamber and displace the gas in the chamber.

In use, the chamber 12, weighted down with water if necessary, and the skirt 16 provides a water resistant flood defence 10, which is self-supporting and need not be held to the plinth 9 other than by its own weight. Support chamber 14 is optional but provides better stability of the main chamber 12, by allowing the main chamber 12 to be further supported by the wall 2. A plurality of chambers 12 can be chained together, joined by a sheet of waterproof but flexible material. That joining sheet can be placed either on the front or rear face of the face of chamber 12. The result is an elongate flood defence which can extend around internal and external corners of building 1 or other construction, to hold back flood water 8. Steps in height are possible between adjoining chained chambers 12. No particular preparation is needed for the defence 10, but a firm base is desirable, for example, a concrete plinth 9 which could be used as a path at other times. Additionally, as shown in this embodiment, an extension 3 b to the damp proof course 3 a of the building can be included against the wall 2 to inhibit water seepage into the building 1. In the installation illustrated a plug 19 of expanding polyurethane foam material has been injected between the cavity of wall 2 to further inhibit water seepage .

Two further arrangements of the defences are shown in FIGS. 2 a and 2 b. In FIG. 2 a a plurality of chambers 22, of the same construction as chamber 12, arranged in a series of hexagonal formations 21 each formation being fitted against another to form a flood defence 20. The formations 21 are deployable quickly and need no extra support. It is possible to fill not only some or all of the chambers 22 of the formations 21 with water, but also the basin area 23 enclosed by the formations. This can be done by allowing flood water into the area 23 by means of a gated passage 24, operable from an upper area of the formation 21. FIG. 2 b shows a section of the chamber 22 along line 2 b-2 b in FIG. 2 a. Shown in this Figure is the valve stem 25 which in use operates a gate in passage 24 for allowing flood water into the basin 23. The floor of the recess can have a water impermeable layer 26, to prevent seepage of water into or out of the basin 23. The defence 20 when filled with water in the basin 23 is particularly effective against flowing flood waters or wave action.

The chambers 22 and/or the basin 23 may be filled with other material besides water for example the chambers could be filled, with concrete or fluidised sand. The basin 23 too could be filled with concrete, aggregate or the like.

FIG. 3 shows a further embodiment of a flood defence 30 having a generally ‘A’ shaped arrangement, comprising two chambers 31 and 32, and a brace 33, all, of which have the same drop stitch formation as the chamber 12 described above. The two chambers 31 and 32 are inclined toward each other to provide a wide base, which allows the flood defence 30 to be self-supporting. The brace 33 provides further strength. A skirt 36 can be used to inhibit water 8 seepage under the defence 30.

The defence 30 can be used in the same manner as the defences 10 and 20, however unlike defence 10, no support 14, is required in this instance. The defence 30 can be linked together to form a chain as shown in FIG. 2 a.

The defences 10, 20 or 30 can be arranged in a row to protect buildings or the like. Multiple layers of defences can be employed to provide additional flood defences or back-up defences.

FIG. 4 shows apparatus 40 formed from one of the hexagonal formations 21 (shown in FIG. 2 a). Six chambers 22, constructed in the manner described above, are connected to form a water dam, in this case in the form of a free-standing hexagonal reservoir 23. This apparatus 40 can be used, as described above, as part of a flood defence, or as shown in this figure, as a free-standing reservoir, for example for use in firefighting, where water has to be supplied by a bowser. The bowser can quickly offload its water into the reservoir and then proceed without delay to collect further water whilst the offloaded water in the reservoir 23 is being used by other fire-fighting appliances. Chambers 22 can be filled with air and then water, although since the apparatus 40 is not being pushed from one side by flood waters when used as a free-standing reservoir, then the water filling of the air inflated chambers 22 is not essential.

Valve 42 is used to fill the chambers 22 with air and/or water. Valve 44 is used to fill the reservoir 23 with water. Flexible cross straps 46 are employed to make the upper sections of the chambers 22 more rigid.

The apparatus 40 can be deflated and stored in a carry bag in or on a fire-fighting appliance or a bowser. Grab handles 48, only one of which has been referenced, can be used for manipulating the apparatus 40 prior to its filling with water. The base of the apparatus 40 may include a flexible water resistant member covering all or part of the underside of the reservoir 23 to reduce or prevent water leakage.

Although a hexagonal construction 40 has been illustrated it will be apparent that other polygon shapes could be employed. For example, in plan the shape could be triangular, square, rectangular, pentagonal, etc.

The embodiments described above are merely examples of the invention. Modifications, variants, equivalents, alternatives etc will be readily apparent to the skilled addressee. 

1. A flood defence or water dam including or comprising at least one inflatable chamber providing a front surface and a rear surface, the front and rear surfaces extending generally parallel and being interconnected by a multiplicity of interconnecting members extending across the chamber, and at least one of the surfaces providing a water barrier.
 2. A flood defence or water dam as claimed in claim 1, wherein the or each chamber is water finable.
 3. A flood defence or water darn as claimed in. claim 2, wherein the or each chamber is not fixed or sealed to the ground.
 4. A flood defence or water darn as claimed in claim 1, further including a skirt located at a lower region of the or each chamber, in use extending toward the water or impending flood water.
 5. A flood defence or water dam as claimed in claim 4, wherein the skirt is arranged to lie on the ground adjacent the or each chamber.
 6. A flood defence or water darn as claimed in claim 5, wherein a substantially watertight seal between the chamber and the skirt is provided.
 7. A flood defence or water dam as claimed in claim 1, wherein one of the surfaces, or both surfaces are substantially impermeable to water.
 8. A flood defence or water dam as claimed in claim 1, wherein the or each chamber is formed from a drop-stitch material.
 9. A flood defence or water darn as claimed in claim 8, wherein said drop stitch material has polymer coated fabric sheets separated by a multiplicity of fibres or threads, each being attached to the inner sides of the sheets.
 10. A flood defence or water dam as claimed in claim 1 further including a chained series of chambers having a sheet material join between adjacent chambers, acting as a hinge and/or a water seal between adjacent chambers.
 11. A flood defence or water dam as claimed in claim 10, wherein the chambers have spacer elements for spacing the chambers from an adjacent wall in use.
 12. A flood defence or water dam as claimed in claim 11, wherein said spacers are formed in the same manner as the chambers claimed in claim
 1. 13. A flood defence or water dam as claimed in claim 9, wherein a pair of chambers are arranged, spaced apart at their lower regions and coming together at their upper regions.
 14. A flood defence or water darn as claimed in claim 1, wherein the chambers are chained together and arranged in a closed polygonal manner when viewed in plan, for example a square or hexagon.
 15. A flood defence or water clam as claimed in claim 14, wherein the chained chambers form a basin within the polygon which is tillable with water.
 16. A flood defence or water dam as claimed in claim 15, wherein the floor of the basin has a water impermeable layer sealed to the chambers of the polygon to form a reservoir.
 17. A series of chained polygonal chambers as claimed in claim 14, connected together at their edges to form a continuous elongate watertight flood defence wall, or a series of reservoirs.
 18. A water darn comprising a plurality of chambers as claimed in claim 1, formed by interconnecting said chambers to form a reservoir for water, optionally having a water resistant base member. 